British Museum coin cleaning

I've noticed several recent posts of coin cleaning. This is the method I've been using for years after watching the British museum video.  Sodium Hydroxide is more commonly known as Caustic Soda & used as a drain cleaner & used with caution can give remarkable results
http://www.dailymotion.com/video/x23sq12_cleaning-coins_lifestyle

Here is an example of a rare previously unrecorded coin, a  copper tanka of  Muhammad bin Tughluq, Sunargaon mint struck for use in Bengal. I cleaned it using my own enhanced version of this BM  treatment

Extremely interesting, thanks for sharing!

(For anyone that can't be bothered to click the link and watch) In the video they used a: 

50g Sodium Hydroxide + 150g Potassium Sodium Tartrate (Rochelle salt) X 1,000ml distilled water

I'll keep a note of this for future reference, you never know 📝 

Bravefoot

Extremely interesting, thanks for sharing!

 

(For anyone that can't be bothered to click the link and watch) In the video they used a: 

50g Sodium Hydroxide + 150g Potassium Sodium Tartrate (Rochelle salt) X 1,000ml distilled water

I'll keep a note of this for future reference, you never know 📝 

I experimented with this and ended up just using Sodium Hydroxide and then poured near boiling water in the small container  holding the coin, it froths up and spits so keep well clear but the results are amazing  and the original patina is left undisturbed

Thanks for sharing. I will try it.!

Vic65

Bravefoot

Extremely interesting, thanks for sharing!

 

(For anyone that can't be bothered to click the link and watch) In the video they used a: 

50g Sodium Hydroxide + 150g Potassium Sodium Tartrate (Rochelle salt) X 1,000ml distilled water

I'll keep a note of this for future reference, you never know 📝 

I experimented with this and ended up just using Sodium Hydroxide and then poured near boiling water in the small container  holding the coin, it froths up and spits so keep well clear but the results are amazing  and the original patina is left undisturbed

 

 

I believe the second component is very important also. To solve the carbonates you need more the caustic solution. 

Awesome, thank you very much.

Hi. I have try it.

First: if you have the components you can produce  a lot of solution. I have for 10 years at least.

I prepare 300 ml only because I use a plastic  container with air tight cover. 

Please use plastic rubber gloves. Solution it is little greasy but if you use naked fingers you feel soon a mild chemical burn.   You will not die but it is  better to use gloves. 

I sunk only modern bronze coin and few romain bronze coin . I was very carefully to not exceed 10 minutes.  

Good result as a lighthouse cleaning bronze bath which you can but it online .  Smell a like. 

Warning if you FORGET about 10 minutes rules you can damage your coin. Really you can disolved it.

After few coins cleaned, in solution I notice some black brown flakes.